I'm using the default theme on a gallery where I post family pics for grandparents and relatives.

They're not the most technically savvy people and I found out recently they were right-clicking to save the web version of the picture, instead of clicking on that to get to the full-sized original. So they have a house full of blurry/jagged 600x400 pics blown up to photo frame size...:-)

So what is the easiest way to either:

(1) Have a size selector - there seems to be code in image.php to "printUserSizeSelector" - but I don't see it as a gallery option.

or

(2) On the image page, insert some text under the gallery breadcrumb that says "if you want to download and print this picture, click on it to see the full-sized version".

Or perhaps both. I didn't see anything in the admin panel to do this...thought I'd ask before I go hacking PHP :-)

I don't understand exactly. Are you asking for a download link? Then use getUnprotectedImageURL() to create such a link.

Or if you want them to just click on that (and also a download counter) you could use that function in combination with the dowloadList plugin. See the documentation of that plugin maybe.

If you want to try out printUserSizeSelector() to see if it works for you, you'll need to enable the viewer_size_image extension.

You could try to add some text and make it noticeable, but that's no guarantee that the user would read it. Really, the only foolproof way is to educate them.

I looked at the viewer_size_image extension and thought that was the trick, but ...it didn't appear to offer a "full size" option. You could setup different sizes, but there was no way to say "make the last choice the full size, regardless of what WxH it is".

Is there a plugin that adds a "download full size" link?

Yes, I realize education is the key but...they're grandparents :-)

I ended up modifying the template and putting a "download for print quality" link with getUnprotectedImageURL().

You could use getFullImageURL() and set the full image protection to "download" on the options (see there for hte correct option). Then they don't even need to use the right click.